Vitamin B is used to treat pellagra, malnutrition and other diseases. Vitamin B belongs to the group of vitamins, the lack of vitamin B6 is easy to cause malnutrition, the lack of vitamin B2 is easy to cause pellagra, B vitamins are mainly used for vitamin B deficiency caused by diseases such as anorexia, pellagra, malnutrition, foot fungus, etc. Some people may experience fatigue, appetite, skin flushing, itching and other adverse reactions. Some people may experience fatigue, loss of appetite, skin flushing, itching and other adverse reactions when using vitamin B. The drug needs to be stopped immediately and is contraindicated for those who are allergic to the drug. It is recommended that patients under the guidance of a doctor, strictly comply with medical advice to use drugs, not blindly use drugs or unauthorized changes in drug dosage, so as not to cause adverse effects on the body, triggering the emergence of other diseases, if discomfort occurs during the period of taking the drug, you need to immediately consult a doctor, to avoid adverse effects on the body.